The Eicosapentaenoic Acid Metabolite 15-Deoxy-δ-Prostaglandin J3 Increases Adiponectin Secretion by Adipocytes Partly via a PPARγ-Dependent Mechanism

The intake of omega-3 polyunsaturated fatty acids (PUFAs), which are abundant in marine fish meat and oil, has been shown to exert many beneficial effects. The mechanisms behind those effects are numerous, including interference with the arachidonic acid cascade that produces pro-inflammatory eicosanoids, formation of novel bioactive lipid mediators, and change in the pattern of secreted adipocytokines. In our study, we show that eicosapentaenoic acid (EPA) increases secreted adiponectin from 3T3-L1 adipocytes and in plasma of mice as early as 4 days after initiation of an EPA-rich diet. Using 3T3-L1 adipocytes, we report for the first time that 15-deoxy-delta(12,14)-PGJ(3) (15d-PGJ(3)), a product of EPA, also increases the secretion of adiponectin. We demonstrate that the increased adiponectin secretion induced by 15d-PGJ(3) is partially peroxisome proliferator-activated receptor-gamma (PPAR-gamma)-mediated. Finally, we show that 3T3-L1 adipocytes can synthesize 15d-PGJ(3) from EPA. 15d-PGJ(3) was also detected in adipose tissue from EPA-fed mice. Thus, these studies provide a novel mechanism(s) for the therapeutic benefits of omega-3 polyunsaturated fatty acids dietary supplementation.